Melanomas are tumors of the skin, less frequently of mucous membranes, some of which are benign. Malignant melanomas are carcinomas of neuroectodermal origin generally derived from melanocytes (pigment-producing cells), sometimes from mucous membranes, the chorioid coat or the meninges. There are several types of malignant melanoma which differ in localization, way of spreading and production of metastases.
Conventional treatment of melanoma includes surgery, radiation or chemotherapy, and the application of biological response modifiers. However, these methods have proven to be insufficient to prevent tumor recurrence, and are complicated by significant side effects. Therefore, it is desirable to develop therapeutic approaches which overcome these drawbacks and can replace or be used in combination with conventional treatment.
Since the immune system seems to be heavily involved in the pathogenesis of this disease, attention has now turned to active immunotherapy, for example based on specific antigens. In melanoma, an example of suitable targets for the production of antibodies and the development of immunotherapeutic approaches are the melanoma associated antigens (MAA), a number of which have been identified and characterized by their molecular weight, for example high molecular weight-melanoma associated antigen (HMW-MAA) with a molecular weight of >1,000,000.
Although not immunogenic in patients with melanoma, HMW-MAA is expressed in at least 80% of melanoma lesions; has a restricted tissue distribution; patients with melanoma possess an immune repertoire that recognizes this antigen and is considered to play a role in the metastatic potential of melanoma.